A liquid crystal panel used in a liquid crystal display device, such as a liquid crystal television set, does not emit light by itself. Thus, the liquid crystal panel uses a backlight unit as a separate lighting device. The backlight unit is installed on the rear side (opposite to the display surface) of the liquid crystal panel, and provided with a chassis with an opening on the liquid crystal panel side; a light source housed in the chassis; and optical members disposed in the opening of the chassis in an opposed manner with respect to the light source and converting the light from light source into planar light to output the light toward the liquid crystal panel, for example.
The optical members of the backlight unit causes the light from the light source to be output toward the liquid crystal panel while providing the light with a predetermined optical effect based on the type of the optical members. For example, a prism sheet collects light from the light source, and a diffuser sheet diffuses light from the light source. An example of the backlight unit including such optical members is described in the following Patent Document 1.
Patent Document 1: Japanese Unexamined Patent Publication No. 2010-44219